I don't recall the freaky speaker connection to the board with a thin wire spiraling around a thick one being discussed. What's up with that?
Not sure adding mass to the case is beneficial to the sound. IME the opposite is often true, but high end customers expectations have been conditioned towards massive cases.
P.S. Still waiting for my series 2 test boards to arrive.
The thin wire around the speaker wire is the current sensing for the protection circuit.
The curly wire is more likely for the output DC offset protection
This makes perfect sense but why is it curled like that? Like a hairstylist did the wire dressing
Their ad has a parts list and a PCB part layout, why don’t you ask them to send it to you? I also bought my PCBs from them, but the parts labels are printed on my boards.
2PCS Swiss NHB 108 Post Power Amplifier Copy One Without Negative Feedback Amplifier Circuit 2 Tubes Parallel (without SCNP)|Amplifier| - AliExpress
2PCS Swiss NHB 108 Post Power Amplifier Copy One Without Negative Feedback Amplifier Circuit 2 Tubes Parallel (without SCNP)|Amplifier| - AliExpress
Those pictures are from the (short) Matej Isak factory tour
Did you see Analog Planet/Michael Fremmers Dartzeel Factory tour, as well?
It is much more extensive:
YouTube
I am sure You will pick up even more interesting info from that tour.
E g the rectifier/soft start resistors used in the 468 (if that is of any interest to NBH 108 Ver 2?)
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Have the parts list from the Dartzeel Manual.. Downloaded it. Tomorrow I will finish the PCB. I will get the missing components. Think I will knock of the ceramic from output resistors. Place a silvermica in between two 0.22 resistors and parralel them so it is 0.11 ohm
Hi all,
I have an original Dartzeel NHB-108B Amplifier that I am having some problems with and found this thread while searching for possible solutions.
The amplifier was lying packed for several months due to some construction activity and when I put it back on, I found that one channel is louder than the other. I have checked everything and have narrowed it down to the amp.
The dealer says that I must send the amp back to the factory to check which is not possible given the current situation and the fact that I am on another continent.
I was hoping that someone can help me diagnose what the problem could be considering many seem to have built a clone with the same schematics. I have pretty basic electronics knowledge and have a multi-meter, soldering kit, etc. I also have access to an oscilloscope, if required.
Thanks in advance.
I have an original Dartzeel NHB-108B Amplifier that I am having some problems with and found this thread while searching for possible solutions.
The amplifier was lying packed for several months due to some construction activity and when I put it back on, I found that one channel is louder than the other. I have checked everything and have narrowed it down to the amp.
The dealer says that I must send the amp back to the factory to check which is not possible given the current situation and the fact that I am on another continent.
I was hoping that someone can help me diagnose what the problem could be considering many seem to have built a clone with the same schematics. I have pretty basic electronics knowledge and have a multi-meter, soldering kit, etc. I also have access to an oscilloscope, if required.
Thanks in advance.
Hi maxzimum
I find it very unlikely that the gain difference has a connection to the amp boards. The gain is determined by two resistors which lead a happy and relatively unstressed life unless the amp is close to full power. Not impossible, but unlikely. And easy to check.
You should make certain it is indeed the amp responsible for the gain difference and put some numbers to it.
Not hard even with only a voltmeter.
What kind of digital inputs does your dac have? In case it is easy to connect a Windows laptop to the dac, checking the gain boils down to running a frequency generator software on the laptop and measuring input and output voltages to and from the amp.
Doable even without a dac using the laptop's built in soundcard but this requires a cable you might not have.
I find it very unlikely that the gain difference has a connection to the amp boards. The gain is determined by two resistors which lead a happy and relatively unstressed life unless the amp is close to full power. Not impossible, but unlikely. And easy to check.
You should make certain it is indeed the amp responsible for the gain difference and put some numbers to it.
Not hard even with only a voltmeter.
What kind of digital inputs does your dac have? In case it is easy to connect a Windows laptop to the dac, checking the gain boils down to running a frequency generator software on the laptop and measuring input and output voltages to and from the amp.
Doable even without a dac using the laptop's built in soundcard but this requires a cable you might not have.